JPS5970706A - Pretreatment of molten iron in torpedo car - Google Patents

Abstract

PURPOSE:To improve the desulfurization efficiency in the conical part of a torpedo car by specifying the movement of a lance when a pretreating agent is blown into molten iron from the lance through the iron receiving and discharging hole of the car. CONSTITUTION:At least the nozzle of a lance 3 for blowing a pretreating agent is immersed in molten iron in a torpedo car 1 through the iron receiving and discharging hole 2 of the car 1. The lance 3 is first located at a position A closest to the conical part 6 of a car 1, and desulfurization is started. After the passage of a fixed time, the lance 3 is moved to a position B closest to the part 6 and opposite to the position A, and desulfurization is carried out for a fixed time. The lance 3 is repeatedly moved between the positions A, B while continuously blowing the desulfurizing agent with a carrier gas even during the movement of the lance 3. The desulfurizing agent may be blown while swinging the lance 3 around a swinging center in the space over the hole 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an effective pretreatment method for hot metal in a mixing car.

The mixed "fc" car bath Q pretreatment method (the desulfurization method will be explained below as a representative example) is generally carried out in a mixed pig iron car 1 as shown in Fig. 1.
Output/Pigtail receiving port (hereinafter simply referred to as receiving port) 2 to lance 3
A method is used in which a desulfurizing agent is immersed in faP and a desulfurizing agent and a carrier gas are blown into the lance through the blowing hole 4 of the lance.

In FIG. 1, numeral 5 indicates hot metal in the pig iron mixer car, 6 shows a conical part of the pig iron mixer car, and 7 shows a desulfurizing agent blowing area. (7m is the desulfurization agent blowing area when the desulfurization agent is blown out in the longitudinal direction of the pig iron car, and 7n is the desulfurization agent blowing out area when the desulfurization agent is blown out in the direction of the double barrel wall.) In Fig. 1, the desulfurization agent is blown out from the desulfurization agent blowing hole 4 by the carrier gas. The desulfurizing agent is blown in the longitudinal direction of the car and toward the wall of the plate drum, but since the lance is located in the center of the pig iron mixer car, there is a limit to how far the desulfurizing agent blowing area 7 can reach the conical part 6. Although the portion 5 was sufficiently desulfurized, the conical portion 6 had a problem in that the desulfurization efficiency was extremely low.

Generally, as a measure to improve desulfurization efficiency, in order to promote the reaction between the hot metal (S) and the desulfurizing agent, the time required for floating is increased, and the contact time between the desulfurizing agent and the hot metal (S, L) is lengthened, and strong stirring is used. There is a method of increasing the contact between the desulfurization agent and the (S) in the hot metal.

As for the former method, ■Lance W@'x method of deepening (Fig. 2 9
There is a method in which O desulfurization agent is injected diagonally downward (Figure 3). (2) The increase in the movement trajectory of the desulfurization agent in the vertical direction increases the contact time required for the reaction between the desulfurization agent and [S] in the bath pig iron, improving the desulfurization efficiency, but the desulfurization efficiency in the conical part of the mixed pig iron car increases. There has been no improvement.

On the other hand, as the latter method, there is a method in which stirring is carried out using an impeller while blowing a desulfurizing agent into the pig iron mixer.

However, since the dearming agent outlet and the impeller are located at the center of the longitudinal axis of the mixed iron car, the vortex removal rate due to stirring can only be achieved in the center of the mixed iron car. If this is not done, the mixed pig iron tank will become over-desulfurized.

The present invention has been made in view of the above-mentioned circumstances, and its feature is that the outlet and receiving ports of the pig iron mixer car are valved so that at least the pretreatment agent blowing hole r is immersed in the hot metal. The pretreatment agent is blown into the hot metal using a carrier gas while the lance is moved forward and backward in the longitudinal direction of the pig iron mixer, or by being swung as a rocking core above the pig iron receiving port. In particular, the present invention provides a method for pre-treatment of mixed base hot pig iron for the purpose of improving the desulfurization efficiency of the conical part of a mixed pig iron car.

The present invention will be explained below based on FIG.

Reference numerals 1 to 7 are the same as those in the conventional method, and the entire explanation of FIG. 1 applies mutatis mutandis.

The lance positions A and B are the positions closest to the conical part 6 in the longitudinal direction of the pig iron mixer car in the outlet/receiving port 2. 8 is a lance drive device that holds the lance suspended, and is located at position A,
It has the function of reciprocating piston movement of B.

FIG. 5 shows the processing pattern τ of the present invention.

The lance 3 is initially located at A, and moves in the direction of B in the figure after starting the desulfurization process or after a certain period of time tA.

At position B, after injecting the desulfurizing agent for tB time, move in direction A. Although tA and tB may be the same time or different, they are generally the same time. In addition, even while the lance is moving, the injection of "Devalue Explosion" continues. t
o is the lance movement time.

In this way, the lance reciprocates between position A and position B to perform desulfurization, and at this time, the desulfurization agent is sufficiently blown into the conical part P and trench as shown in Figure 4 (a). As a result, desulfurization of the hot metal in the conical region progresses.

Figure 5 shows an example of the treatment pattern of the present invention, in which the amount of defiltration agent blown is changed from midway through the treatment in order to improve the desulfurization efficiency.
” You may change the method of blowing.

EXAMPLE The desulfurization treatment conditions according to the present invention are shown in No. 16, and the desulfurization results are shown in Table 2.

Table 1 Desulfurization treatment conditions Table 2 Desulfurization results The results show that the present invention is superior to the conventional method.

In the above embodiment, a case has been described in which the pig iron mixer car is advanced and retreated in the longitudinal direction with the lance suspended and held, but the present invention is not limited to this, and the ψrie uses the space above the outlet and pigtail mouth as the swinging core. A similar effect can be achieved by swinging the lance in the longitudinal direction of the pig iron mixer. Furthermore, the present invention may be implemented in a vessel other than a pig iron mixing car that accommodates melt metal. Furthermore, the present invention provides hot metal pretreatment other than desulfurization, such as de[P].

Similar effects have been shown in treatments such as dehydration (S1) and dehydration (MnJ), and there is no doubt that it can be widely applied.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the pretreatment method for hot metal in a mixed pig iron car, where (a) is a cross-sectional view, (b) is a schematic plan view, and Figure 2 shows a mode in which the lance immersion depth is variable. 3 is a diagram showing a shallow case and a deep case, respectively, and FIG. 3 is an illustration of a pretreatment agent injection pattern. Fig. 4 shows an embodiment of the present invention; a) is a schematic vertical sectional view (bl is a schematic plan view); Fig. 5 shows a hot metal desulfurization treatment pattern according to an embodiment of the present invention (piston motion). 1... Pig mixer car 2... Outlet/receiver port 3... Lance 4... Blowout hole 5... Pig mixer car Plate body 6...Conical part of the pig iron mixer 7...Desulfurizing agent blowing area Applicant Nippon Steel Corporation Agent Kiyoshi Kosara - Karasu Figure 1 (d) (b
) Figure 2 Figure 3 Figure 5 7q+ itM'11%'l ->

Claims (1)

[Claims] Through the outlet/receiving port of the pig iron mixer car, at least a lance immersed in the hot metal at the pretreatment agent blowout hole is moved forward and backward along the longitudinal direction of the pig iron mixer car, or the space above the above-mentioned pig iron receiving port is moved forward and backward along the longitudinal direction of the pig iron mixer car. A method for pre-treating hot metal in a mixed pig iron car, characterized by blowing a pre-treating agent into the hot metal with a carrier gas while swinging as a whole swinging core.